De novo 13q paracentric inversion in a boy with cleft palate and mental retardation.

A paracentric inversion in chromosome 13, inv(13)(q12q22), is described in a boy with mild mental retardation and multiple minor anomalies. Bromodeoxyuridine-late replication studies showed no changes in the replication pattern of bands in the abnormal chromosome 13. The relation between the proband's phenotype and his inv(13) is unclear.